1. Field of the Invention
The invention relates to a device for the removal of injection moldings from the mold of an injection molding machine having a movable and a fixed die chucking plate with a drive unit for moving an actuating element linearly toward or away from the mold.
2. Description of the Prior Art
EP 0 724 944 discloses an ejector unit with a servomotor which is fastened to the movable die chucking plate and has a stator and a rotor, the rotor having fastened to it a hollow shaft possessing a ball-screw spindle nut, through which a ball-screw spindle shaft is capable of being moved forward and backward.
GB 297 22 964 discloses an ejector unit for an injection molding machine, in which the spindle is connected rigidly to the ejector plate and carries a nut which is rotatable via an electric motor.
In the above-mentioned ejector units, limits are placed in a disadvantageous way on the configuration of the ball-screw spindle nut, since the latter, together with the hollow shaft, is to be as small as possible in terms of its outside diameter.
DE 42 28 140 A1 discloses an ejector unit, in which an electric motor is seated as an ejector drive on a base capable of being attached to the mold carrier plate, said electric motor being in constant adjusting connection with a plurality of rotationally driveable threaded spindles, an ejector plate being capable of being adjusted on the threaded spindles via nut threads, the ejector plate carrying an ejector ram passing through the base and the mold carrier plate.
This design has the disadvantage that a large amount of space is required due to the arrangement of the electric motor and of the gear device.
EP 0 853 537 B1 discloses a device for the treatment and/or removal of injection moldings on an injection molding machine for the processing of plasticizable materials, the drive unit of which is a hollow-shaft motor receiving at least partially within it the actuating element, the device being supported on the mold closing device at a support element.
Provided centrally in relation to the injection axis of the injection molding machine is a space for arranging an ejector, a core extractor or an unscrewing mechanism, that is to say a device for the treatment and/or removal of injection moldings.
Due to the arrangement of the support element, the proposed ejector device requires a relatively large space, thus leading to obstructions on the closing side of the injection molding machine.